Railway signaling



June 19, 1934. R. R. KEMMERER RAILWAY SIGNALING Filed 001;. 17, 1951 R YE e HQ "QM m \h kw R XQ X Patented June 19, 1934 RAILWAY SIGNALING RalphR. Kemmerer, Swissvale, Pa., assignor to The Union Switch & SignalCompany, Swissvale, Pa., a, corporation of Pennsylvania ApplicationOctober 17,

Claims.

My present invention-relates to a railway block .signal and automaticstop control particularly suitable for monorail installations, andcomprises circuits adapted to operate signals or the like at 5theentrance to each block and to control the position of a trippingdevice in accordance with traffic conditions. The invention includesmeans for providing in monorail installations the equivalentof the'usual continuous track circuits, and means responsive thereto forindicating the condition of the track ahead, and for normallycausingoperationofa tripping device at the entrance to ablock when thatblock or the first part of the succeeding block is occupied whilesuppressing the operation of the tripping mechanism under oertainconditions to permit a following car or train to enter an occupiedblock.

For a better understanding of the invention, reference may be had to theaccompanying drawing in which is diagrammatically illustrated, a trainsignaling and control system for monorail installations embodying theinvention.

In the drawing, the running rail of a monorail system is indicated at Z,and an auxiliary rail or trolley at X. Rail X, which is so positioned asto be engaged by any suitable contactor carried by a car travelling onthe running rail Z, serves, together with track relays, to complete thetrack circuits for each block 2T, 4'1 and GT of the rail Z. In theparticular embodiment of the invention illustrated, rail Z is notsubdivided and hence is common to all track circuits, while rail X issubdivided into two insulated sections per block. each of which isconnected to rail Z through the secondary of a transformer l.Alternating current is supplied to the primary of each transformer 1from any suitable source the terminals of which are indicated by BX andCX. The track circuits thus formed, divide each block into two sectionsdesignated in the drawing by the subscripts 1- and 2.

At the entrance to each block is arr automatic tripping mechanism forcooperation with stopping mechanism carried by the car; mechanisms 4Vand 6V at the entrance to track sections 4T and GT respectively beingindicated diagrammatically on the drawing. The construction of thesemechanisms is immaterial to the present invention. Any mechanism of thetype which is biased into tripping position and which, when current issupplied to the winding thereof, is held in inoperative position, wouldbe suitable. At the and T6 at 4 and 6 respectively. Signals 4 and 1931,Serial No. 569,462

6 are controlled by the home and distant relays associated with blocks4T and ST respectively. In the embodiment illustrated these signals areassumed to be of the colored light type in which green indicates clear,yellow caution, and red 6 danger but, as will be apparent as thedescription proceeds, the signals could be of the semaphore type with orwithout the addition of lights; the controlling circuits being equallysuitable for any type of three indication signal.

As the circuits for mechanisms 4V and 6V and for the signals 4 and 6 arecontrolled by the track and home relays, the circuits for these relayswill now be described.

Track relay 4T1R associated with track section 4T1 has its controlelement connected across the rail X and auxiliary rail'or trolley Z soas to be energized by the track current when block 4T1 is unoccupied.One side of the local element of relay 4T1R is connected to one terminalCX of a 7 source ofalternating electromotive force, and the other sidethrough a stick circuit including itsiown top contact is connected tothe other terminal BX of the source. The pick-up circuit for relay 4T1Ris from source BX through a back contact of track relay 4T2R associatedwith block portion 4T2, and a pair of contacts 8 which are carried bytripping mechanism 4V and are closed only when the mechanism is intripping position. The circuits for track relay 6T1R are similar tothose of track relays 4T1 and hence need no separate description.

For convenience contacts 8 have been shown dissociated from themechanism 4V but it will be understood that in practice, these contactswill be so positioned as to be closed when the tripping arm of themechanism is moved into position to engage the train carried automaticstop.

The circuits for the home relay 4HR for signal 4 are as follows: SourceCX is connected to one side of the winding, and the other side isconnected over its own top contact and top contacts of relays 4T1R,6T1Rand 4T2R to BX. The top contact of relay 4BR, in this circuit isbridged by a pair of contacts 9 which, like contacts 8, are carried byautomatic tripping mechanism 4V although for convenience are showndissociated therefrom. Like contacts 8, contacts 9 are closed when themechanism is'in tripping position.' 7

Thus, when a car enters track section 4T1, relay 4T1R will drop itsarmatures opening the circuit for relay 4HR which can not again beenergized until relay 4T1R has been energized and until the car hasproceeded through track section 4T2 and the circuit of relay 4T2R hasagain been closed. Even then relay 4HR will not be energized unless theautomatic mechanism 4V has gone to stopping position and closed contacts9. When this occurs relay 4HR, will pick up and the stick circuit overits own top contact will be closed to shunt contacts 9.

Relay 4T2R has its control element connected across the rails X and Z attrack section 4T2. One side of its local element is connected toone sideCX of a source of alternating voltage and the other side connected to BXthrough a stick circuit including its own armature and top contact. Apick-up circuit is provided for this relay through a back contact ofrelay 6T1R. Thus, after a car has entered track section 4T2, relay'4T2Rcan not be reenergized until after I'BIZJYGTIR has dropped its armature.V

For convenience in illustrating the circuits of the stopping mechanism4V, the winding 4VW thereof has been shown dissociated from themechanism. It will be understood that when current flows through thewinding 4VW the mechanism 4V will be held in inoperative or normalposition and that when the circuit of winding 4VW is open the mechanismmoves into operative or stopping position.

The circuits for the winding 4VW of mechanism 4V are as follows:

CX is connected to one side of the winding 4VW, and the other side isconnected through a top contact of relay 4T1R and a top contact of:relay 4'I-IR to BX. When relay 4T1R is deenergized due to a trainentering track section 4T1 and the stopping mechanism 4V is in itsinoperative position with contacts 8 open, the circuitior winding 4VW isclosed through a back contact of relay4T1R,'a pair'of contacts 10carried by mechanism 4V and so positioned'as to be closed when themechanism is in its inoperative position, and top contacts of relays6T1R and 4T2R. This circuit is for the purpose of holding mechanism 4Vin its inoperative position until all cars of the train have passed overit. Still another circuit for winding 4VW is provided through the backcontact of relay 4T1R and a back contact of relay 2T2R. This lastcircuit permitsa following train to enter the occupied block withoutbeing stopped by the automatic mechanism. 7

,7 If -a train enters track section 4T1 from section 2T2-and-there is notrain in'blockfiT, the'entrance of the train into block 4T1 shunts thecontrol element of relay 4T1R causing it to drop its armature and openthe circuit for' relay 4I-IR. The opening of the top contacts of trackrelay 4T1R does not cause the stopping-mechanism'4V to go to trippingposition because the circuit for winding 4VW is still closed throughcontacts 10, -(mechanism- 4V being in inoperative position) and the topcontacts of relays '6T1R and 4T2R. As the train enters track section4T2, however, this latter circuit fOI the winding 4VW is openedat thetop-contact of relay'4T2R'with the result that mechanism 4V will go tostopping position. This closes the circuit for relay 4T1-R which relaywill then stay picked up through its-stick circuit, the control elementthereof being'no longer shunted by the car. The automatic-mechanism 4V,however, will stay in tripping position because the circuit for winding4VW is 'held open at the top contact of relay 4I-IR. Iffhowever, whenthe train entered track-section 4T2 a following car was in track section2T2 then the automatic mechanismwould not go to tripping position 'forthere would be a circuit for its windings through the "back locating thestopping mechanism 4V a given dis- ;tance ahead of the insulated jointseparating sections 2T2 and 4T1, so that if the train is moving at lessthan a given speed when it enters section 4T1, the circuit for 4Vthrough a back contact or 4T'1R and a back contact of 2T2R will beclosed before the tripping device on the train reaches.

mechanism 4V, and the train can then proceed Without an automatic brakeapplication.

The circuit for relay 4DR is from source BX over a top contact of relay6BR, contacts 11 which are carried 'by mechanism 6V and are closed whenthe mechanism is in inoperative position, top contact of relay 4HRandthewinding of relay 4DR to CX.

Relays 4l-IR and 4DR and mechanism 4V control the light signals G, Y andR for signal 4. The circuit for the green or clear light G is frombattery B over a pair of contacts 12 carried by mechanism 4V and closedwhen the mechanism is in inoperative position, and over top contacts ofrelays 4HR and 4DH. As relay 4DR will be deenergized over the topcontacts of relay 6HR' if there is a car in block GT or in the firstportion of the succeeding block andrelay 4I-IR will be 'deenergized ifthere is a car in block 4T or in block sec- F tion'6'I'1, it followsthat the lighting of clear light G for signal 4 indicates that there areat least two and a half clear blocks ahead of signal 4. It alsoindicates that mechanisms 4V and 6V are each in inoperative position asthe circuit for relay I:

4DR, is over contacts 11 of mechanism 6V and that of the green light Gis over contacts 12 of mechanism 4V. The circuit for caution light Y forsignal 4"is over'contacts 12, top contact of relay 4HR and back contactsof relay 4DR. Thus, if ii the yellow light Y is lighted at signal 4 anindication is given that there is a train in the latter portion of blockGT or in the first portion of the succeeding block or that, for someother reason, mechanism 6V is in stopping position. One circuit fordanger light R for signal 4 is over contacts 12 and back'contact ofrelay 4I-IR. Another circuit for this light is over a pair-of contactsl3 carried by -mechanism 4V and closed when the mechanism is in stoppingposition. Thus, thedisplay of a red light at signal 4 indicates either atrain in blck 4T or in block section 6T1 or mechanism 4V is in trippingposition. It will be noted that the circuits for light R aresuch thata-following train receives a stop signal even when mechanism 4V is heldin inoperative position by the special circuits described for winding4VW.

The preferred embodiment of the invent-ion'has now been described. Itwill be apparent that the new circuits provide a complete system or 1:

control for block signals and for the track elements of automaticstopping devices for a monorail installation and that the system soprovided is responsive to traffic conditions and is substantiallyself-checking to prevent false clear indica- .4::

tions. Moreover the system is comparatively simple and lends -itselfreadily to expansion or contraction should it be desiredto'change-either the number of clear blocks indicated "by a particular.

signal or the number of signal indications to be displayed. Although theinvention is particularly applicable to monorail installation, and hasso been described, obviously the novel features thereof might beadvantageously employed on ordinary two rail trackways handling trafiicin one direction only.

The following is claimed:

1. An automatic block signaling system for railroads comprising incombination, two rails, two track relays per block each having itscontrol element connected across said rails, one of said rails beingsubdivided into two sections per block, means for impressing analternating electromotive force between each section of the subdividedrail and said other rail to provide track current for the controlelements of said relays, a stick circuit for the local element of eachtrack relay including its own top contact, a pick-up circuit for thelocal element of each track relay controlled over a back contact of thetrack relay of the next succeeding section of the rails whereby a trackrelay which has dropped its armature due to shunting of the controlelement thereof can not again raise its armature until the controlelement of the next track relay has been shunted, home and distantrelays for each block controlled by top contacts of said track relays,automatic tripping devices, one located at the entrance to each blockand each carrying a pair of contacts adapted to be closed only when thedevice is in tripping position, the said pick-up circuit for the localelement of the track relay for the first section of each block includingthe pair of contacts of the tripping device for said block, eachtripping device having a control winding which when energized maintainsthe device in inoperative position, and a circuit for which iscontrolled over a top contact of the home relay for the associated blockand a top contact of the track relay for the first section of suchassociated block.

2. An automatic block signal and train stop control for unidirectionaltraiiic comprising in combination two rails, two track relays for eachblock each having its control element connected across said rails, apick-up circuit for the local elements of each track relay controlledover a back contact of the next succeeding track relay, home and distantrelays controlled by said track relays, tripping devices of the typewhich are normally biased into operative position but which when currentis supplied to a winding thereof are held in inoperative position,circuits for the windings of said devices closed over top contacts ofsaid track and home relays under clear or caution conditions, signalsfor each block controlled by the said home and distant relays thereofand means, including additional circuits for the windings of saiddevices, for maintaining the windings of said devices energized undercertain conditions when the first mentioned circuits thereof are openedto permit a following train to enter an occupied block.

3, The combination according to claim 2 wherein the pick-up circuit forthe track relay associated with the first portion of each block includesa pair of contacts which are carried by the device associated with thatblock and are closed when said device is in tripping position and thesaid additional circuit for the device of any one block is controlledover back contacts of the track relay associated with the first portionof that block and of the track relay associated with the last portionor" the preceding block whereby one train following within a block ofanother train may enter a block of which the latter portion is occupiedwithout interference from the tripping device associated with thatblock.

4. In an automatic block signal and train stop system for monorailinstallations, the combination including a running rail and an auxiliaryrail sub-divided into two portions per block, track relays having theircontrol elements connected across said rails for completion of twocontinuous track circuits per block, and a tripping device for eachblock of the type normally biased to tripping position but held ininoperative position when the circuit for a winding thereof is closed,the winding of said device being normally energized over a top contactof the track relay associated with the first portion of the block with,

which the device is associated, and two additional circuits for thewinding of said device each connected to the back contact of the trackrelay associated with the first portion of the block with which thedevice is associated, one of said additional circuits being controlledover top contacts of the two next succeeding track relays and includinga pair of contacts which are carried by said device and which are closedwhen the device is in inoperative position, and the other of saidadditional circuits being controlled over a back contact of the nextpreceding track relay, whereby shunting of the control element of atrack relay associated with the first portion of a block does notnecessarily cause the tripping device at that block to go to trippingposition and shunting of the control element of the track relayassociated with the last portion of a block does not cause the deviceassociated with that block to go to tripping position if the controlelement of the track relay associated with the last portion of thepreceding block has already been shunted.

5. An automatic block signal and train stop control system including incombination two rails subdivided by continuous track circuits into twoportions per block, a track relay for each block portion having itscontrol element connected across said rails for completion of the trackcircuit thereof, each of said track relays having a stick circuit forthe local element thereof and a pick-up circuit controlled over backcontacts of the next receding track relay, a home relay for each blockcontrolled over its own top contact and over top contacts of both trackrelays for that block and of the track relay associated with the firstportion of the next block, a distant relay for each block controlledover top contacts of the home relay for the next block, a signal at theentrance of each block controlled to three positions by said home anddistant relays, a tripping type normally biased into tripping positionbut held inoperative when current is supplied to a winding thereof, anormal circuit for the winding of each device controlled over a topcontact of device adjacent the entrance to each block of the the trackrelay associated with the first portion of the block in which the deviceis located and over a top contact of the home relay for that block; aholding circuit for the winding of each device controlled over a backcontact of the track relay associated with thefirst portion of the blockin which the device is located and top contacts of the two nextsucceeding relays and a permissive circuit for the winding of eachdevice controlled over back contacts of the track relay associated withthe first portion of the block in which the device is located and of thetrack relay associated with the last portion of the preceding block,each of said devices carrying two pairs of contacts each of which areclosed when the device is in trip-,

-ping-positioinoneiof saidpairs-of contacts being in the pick-up'circuitcf the track relay associated with-the first-portion of the block "inwhich the 7 device is locatecLthe other of said pairs ofcontacts beingin the circuit'of the home relay and in parallelwith the portion thereofwhich includes the top contact of that re1ay,'each of said devicescarrying two other pairs'of contacts each of which the circuit of thedistant" relay associated with the block preceding that inwhich thedevice is located.

RALPH R. KEMMERER.

